This invention relates to tufting machines and more particularly to a tufting machine wherein certain of the moving elements in the head of the machine are cooled by water.
Tufting machines which produce carpet, basically include a large frame having a head within which a rotatable mainshaft is mounted and from which needle driving structure is supported for reciprocating a multiplicity of needles. The frame also includes a bed within which oscillating loopers or hooks are mounted for cooperating with the needles to form loops of yarn, knives being used in conjunction with the hooks to cut the loops in many tufting machines. As the tufting art has developed, there have been a substantial number of innovations to obtain unique patterning effects. One such innovation has been to shift the needles laterally in accordance with a pattern. Another innovation has been to provide each needle with a sew/no-sew capability by mounting the needles on individual needle carriers which are reciprocated selectively by either being latched to or disengaged from a reciprocating latch bar, the latter being reciprocably driven continuously from mechanism driven by the rotating mainshaft. When latched to the latch bar, the needle reciprocates into cooperation with the hook to form a loop. The latching occurs by means of latch pins on pneumatic cylinders driven in accordance with a pattern. Machines of this type are known as controlled needle machines, and when each needle is individually controlled in this manner, it is known as an individual controlled needle machine.
A recent development in the tufting art is to combine the individual control needle machine concept with the shifting needle concept, and to feed the backing material intermittently. This provides a tufting machine wherein the needles may be threaded with a number of different yarns, e.g., yarns of different colors, and a needle having a yarn of a particular color may be inserted into the backing at any of a selected number of locations so that extremely precise multi-color patterns may be produced similar to the fine woven carpets produced by looms.
Tufting machines generally have been constructed from steel. However, as machine speeds have increased, lighter weight structural materials such as aluminum have been considered for the moving parts. The needles, however, because of the frictional forces resulting from penetration of the backing and contacting of the hooks during loop formation are required to be constructed from the stronger harder steel. Other structure and parts additionally should be constructed from steel. When lighter weight materials have been used in conjunction with steel major problems have occurred due to the different thermal expansion rates of these different materials. Thus, when using an aluminum reciprocating needle bar the aluminum expands a substantially greater amount than the remaining materials and the needles have tended to go off gauge, i.e., the needles may not properly cooperate with the hooks. When there is a shiftable needle bar driven from one end of the machine such that the needle bar cannot expand at that one end, all the expansion occurs in one direction and the needles at the other end may be off gauge. Still, it is highly desirable to reduce the mass of the reciprocating elements and the shiftable elements such as the needle bar so that higher speeds may be attainable.